1 files changed, 540 insertions, 0 deletions
diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
new file mode 100644
index 000000000000..c2374df9abae
--- /dev/null
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -0,0 +1,540 @@
+ /* Algorithms supported by virtio crypto device
+  *
+  * Authors: Gonglei <[email protected]>
+  *
+  * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
+  *
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or
+  * (at your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *
+  * You should have received a copy of the GNU General Public License
+  * along with this program; if not, see <http://www.gnu.org/licenses/>.
+  */
+
+#include <linux/scatterlist.h>
+#include <crypto/algapi.h>
+#include <linux/err.h>
+#include <crypto/scatterwalk.h>
+#include <linux/atomic.h>
+
+#include <uapi/linux/virtio_crypto.h>
+#include "virtio_crypto_common.h"
+
+/*
+ * The algs_lock protects the below global virtio_crypto_active_devs
+ * and crypto algorithms registion.
+ */
+static DEFINE_MUTEX(algs_lock);
+static unsigned int virtio_crypto_active_devs;
+
+static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
+{
+	u64 total = 0;
+
+	for (total = 0; sg; sg = sg_next(sg))
+		total += sg->length;
+
+	return total;
+}
+
+static int
+virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
+{
+	switch (key_len) {
+	case AES_KEYSIZE_128:
+	case AES_KEYSIZE_192:
+	case AES_KEYSIZE_256:
+		*alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
+		break;
+	default:
+		pr_err("virtio_crypto: Unsupported key length: %d\n",
+			key_len);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int virtio_crypto_alg_ablkcipher_init_session(
+		struct virtio_crypto_ablkcipher_ctx *ctx,
+		uint32_t alg, const uint8_t *key,
+		unsigned int keylen,
+		int encrypt)
+{
+	struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
+	unsigned int tmp;
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
+	int err;
+	unsigned int num_out = 0, num_in = 0;
+
+	/*
+	 * Avoid to do DMA from the stack, switch to using
+	 * dynamically-allocated for the key
+	 */
+	uint8_t *cipher_key = kmalloc(keylen, GFP_ATOMIC);
+
+	if (!cipher_key)
+		return -ENOMEM;
+
+	memcpy(cipher_key, key, keylen);
+
+	spin_lock(&vcrypto->ctrl_lock);
+	/* Pad ctrl header */
+	vcrypto->ctrl.header.opcode =
+		cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
+	vcrypto->ctrl.header.algo = cpu_to_le32(alg);
+	/* Set the default dataqueue id to 0 */
+	vcrypto->ctrl.header.queue_id = 0;
+
+	vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
+	/* Pad cipher's parameters */
+	vcrypto->ctrl.u.sym_create_session.op_type =
+		cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
+	vcrypto->ctrl.u.sym_create_session.u.cipher.para.algo =
+		vcrypto->ctrl.header.algo;
+	vcrypto->ctrl.u.sym_create_session.u.cipher.para.keylen =
+		cpu_to_le32(keylen);
+	vcrypto->ctrl.u.sym_create_session.u.cipher.para.op =
+		cpu_to_le32(op);
+
+	sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
+	sgs[num_out++] = &outhdr;
+
+	/* Set key */
+	sg_init_one(&key_sg, cipher_key, keylen);
+	sgs[num_out++] = &key_sg;
+
+	/* Return status and session id back */
+	sg_init_one(&inhdr, &vcrypto->input, sizeof(vcrypto->input));
+	sgs[num_out + num_in++] = &inhdr;
+
+	err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
+				num_in, vcrypto, GFP_ATOMIC);
+	if (err < 0) {
+		spin_unlock(&vcrypto->ctrl_lock);
+		kzfree(cipher_key);
+		return err;
+	}
+	virtqueue_kick(vcrypto->ctrl_vq);
+
+	/*
+	 * Trapping into the hypervisor, so the request should be
+	 * handled immediately.
+	 */
+	while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
+	       !virtqueue_is_broken(vcrypto->ctrl_vq))
+		cpu_relax();
+
+	if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
+		spin_unlock(&vcrypto->ctrl_lock);
+		pr_err("virtio_crypto: Create session failed status: %u\n",
+			le32_to_cpu(vcrypto->input.status));
+		kzfree(cipher_key);
+		return -EINVAL;
+	}
+
+	if (encrypt)
+		ctx->enc_sess_info.session_id =
+			le64_to_cpu(vcrypto->input.session_id);
+	else
+		ctx->dec_sess_info.session_id =
+			le64_to_cpu(vcrypto->input.session_id);
+
+	spin_unlock(&vcrypto->ctrl_lock);
+
+	kzfree(cipher_key);
+	return 0;
+}
+
+static int virtio_crypto_alg_ablkcipher_close_session(
+		struct virtio_crypto_ablkcipher_ctx *ctx,
+		int encrypt)
+{
+	struct scatterlist outhdr, status_sg, *sgs[2];
+	unsigned int tmp;
+	struct virtio_crypto_destroy_session_req *destroy_session;
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	int err;
+	unsigned int num_out = 0, num_in = 0;
+
+	spin_lock(&vcrypto->ctrl_lock);
+	vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
+	/* Pad ctrl header */
+	vcrypto->ctrl.header.opcode =
+		cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
+	/* Set the default virtqueue id to 0 */
+	vcrypto->ctrl.header.queue_id = 0;
+
+	destroy_session = &vcrypto->ctrl.u.destroy_session;
+
+	if (encrypt)
+		destroy_session->session_id =
+			cpu_to_le64(ctx->enc_sess_info.session_id);
+	else
+		destroy_session->session_id =
+			cpu_to_le64(ctx->dec_sess_info.session_id);
+
+	sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
+	sgs[num_out++] = &outhdr;
+
+	/* Return status and session id back */
+	sg_init_one(&status_sg, &vcrypto->ctrl_status.status,
+		sizeof(vcrypto->ctrl_status.status));
+	sgs[num_out + num_in++] = &status_sg;
+
+	err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
+			num_in, vcrypto, GFP_ATOMIC);
+	if (err < 0) {
+		spin_unlock(&vcrypto->ctrl_lock);
+		return err;
+	}
+	virtqueue_kick(vcrypto->ctrl_vq);
+
+	while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
+	       !virtqueue_is_broken(vcrypto->ctrl_vq))
+		cpu_relax();
+
+	if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
+		spin_unlock(&vcrypto->ctrl_lock);
+		pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
+			vcrypto->ctrl_status.status,
+			destroy_session->session_id);
+
+		return -EINVAL;
+	}
+	spin_unlock(&vcrypto->ctrl_lock);
+
+	return 0;
+}
+
+static int virtio_crypto_alg_ablkcipher_init_sessions(
+		struct virtio_crypto_ablkcipher_ctx *ctx,
+		const uint8_t *key, unsigned int keylen)
+{
+	uint32_t alg;
+	int ret;
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+
+	if (keylen > vcrypto->max_cipher_key_len) {
+		pr_err("virtio_crypto: the key is too long\n");
+		goto bad_key;
+	}
+
+	if (virtio_crypto_alg_validate_key(keylen, &alg))
+		goto bad_key;
+
+	/* Create encryption session */
+	ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
+			alg, key, keylen, 1);
+	if (ret)
+		return ret;
+	/* Create decryption session */
+	ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
+			alg, key, keylen, 0);
+	if (ret) {
+		virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
+		return ret;
+	}
+	return 0;
+
+bad_key:
+	crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+	return -EINVAL;
+}
+
+/* Note: kernel crypto API realization */
+static int virtio_crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,
+					 const uint8_t *key,
+					 unsigned int keylen)
+{
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+	int ret;
+
+	if (!ctx->vcrypto) {
+		/* New key */
+		int node = virtio_crypto_get_current_node();
+		struct virtio_crypto *vcrypto =
+				      virtcrypto_get_dev_node(node);
+		if (!vcrypto) {
+			pr_err("virtio_crypto: Could not find a virtio device in the system");
+			return -ENODEV;
+		}
+
+		ctx->vcrypto = vcrypto;
+	} else {
+		/* Rekeying, we should close the created sessions previously */
+		virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
+		virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
+	}
+
+	ret = virtio_crypto_alg_ablkcipher_init_sessions(ctx, key, keylen);
+	if (ret) {
+		virtcrypto_dev_put(ctx->vcrypto);
+		ctx->vcrypto = NULL;
+
+		return ret;
+	}
+
+	return 0;
+}
+
+static int
+__virtio_crypto_ablkcipher_do_req(struct virtio_crypto_request *vc_req,
+		struct ablkcipher_request *req,
+		struct data_queue *data_vq,
+		__u8 op)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
+	unsigned int ivsize = crypto_ablkcipher_ivsize(tfm);
+	struct virtio_crypto_ablkcipher_ctx *ctx = vc_req->ablkcipher_ctx;
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	struct virtio_crypto_op_data_req *req_data;
+	int src_nents, dst_nents;
+	int err;
+	unsigned long flags;
+	struct scatterlist outhdr, iv_sg, status_sg, **sgs;
+	int i;
+	u64 dst_len;
+	unsigned int num_out = 0, num_in = 0;
+	int sg_total;
+	uint8_t *iv;
+
+	src_nents = sg_nents_for_len(req->src, req->nbytes);
+	dst_nents = sg_nents(req->dst);
+
+	pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
+			src_nents, dst_nents);
+
+	/* Why 3?  outhdr + iv + inhdr */
+	sg_total = src_nents + dst_nents + 3;
+	sgs = kzalloc_node(sg_total * sizeof(*sgs), GFP_ATOMIC,
+				dev_to_node(&vcrypto->vdev->dev));
+	if (!sgs)
+		return -ENOMEM;
+
+	req_data = kzalloc_node(sizeof(*req_data), GFP_ATOMIC,
+				dev_to_node(&vcrypto->vdev->dev));
+	if (!req_data) {
+		kfree(sgs);
+		return -ENOMEM;
+	}
+
+	vc_req->req_data = req_data;
+	vc_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
+	/* Head of operation */
+	if (op) {
+		req_data->header.session_id =
+			cpu_to_le64(ctx->enc_sess_info.session_id);
+		req_data->header.opcode =
+			cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
+	} else {
+		req_data->header.session_id =
+			cpu_to_le64(ctx->dec_sess_info.session_id);
+	    req_data->header.opcode =
+			cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
+	}
+	req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
+	req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
+	req_data->u.sym_req.u.cipher.para.src_data_len =
+			cpu_to_le32(req->nbytes);
+
+	dst_len = virtio_crypto_alg_sg_nents_length(req->dst);
+	if (unlikely(dst_len > U32_MAX)) {
+		pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
+		err = -EINVAL;
+		goto free;
+	}
+
+	pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
+			req->nbytes, dst_len);
+
+	if (unlikely(req->nbytes + dst_len + ivsize +
+		sizeof(vc_req->status) > vcrypto->max_size)) {
+		pr_err("virtio_crypto: The length is too big\n");
+		err = -EINVAL;
+		goto free;
+	}
+
+	req_data->u.sym_req.u.cipher.para.dst_data_len =
+			cpu_to_le32((uint32_t)dst_len);
+
+	/* Outhdr */
+	sg_init_one(&outhdr, req_data, sizeof(*req_data));
+	sgs[num_out++] = &outhdr;
+
+	/* IV */
+
+	/*
+	 * Avoid to do DMA from the stack, switch to using
+	 * dynamically-allocated for the IV
+	 */
+	iv = kzalloc_node(ivsize, GFP_ATOMIC,
+				dev_to_node(&vcrypto->vdev->dev));
+	if (!iv) {
+		err = -ENOMEM;
+		goto free;
+	}
+	memcpy(iv, req->info, ivsize);
+	sg_init_one(&iv_sg, iv, ivsize);
+	sgs[num_out++] = &iv_sg;
+	vc_req->iv = iv;
+
+	/* Source data */
+	for (i = 0; i < src_nents; i++)
+		sgs[num_out++] = &req->src[i];
+
+	/* Destination data */
+	for (i = 0; i < dst_nents; i++)
+		sgs[num_out + num_in++] = &req->dst[i];
+
+	/* Status */
+	sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
+	sgs[num_out + num_in++] = &status_sg;
+
+	vc_req->sgs = sgs;
+
+	spin_lock_irqsave(&data_vq->lock, flags);
+	err = virtqueue_add_sgs(data_vq->vq, sgs, num_out,
+				num_in, vc_req, GFP_ATOMIC);
+	virtqueue_kick(data_vq->vq);
+	spin_unlock_irqrestore(&data_vq->lock, flags);
+	if (unlikely(err < 0))
+		goto free_iv;
+
+	return 0;
+
+free_iv:
+	kzfree(iv);
+free:
+	kzfree(req_data);
+	kfree(sgs);
+	return err;
+}
+
+static int virtio_crypto_ablkcipher_encrypt(struct ablkcipher_request *req)
+{
+	struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
+	struct virtio_crypto_request *vc_req = ablkcipher_request_ctx(req);
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	int ret;
+	/* Use the first data virtqueue as default */
+	struct data_queue *data_vq = &vcrypto->data_vq[0];
+
+	vc_req->ablkcipher_ctx = ctx;
+	vc_req->ablkcipher_req = req;
+	ret = __virtio_crypto_ablkcipher_do_req(vc_req, req, data_vq, 1);
+	if (ret < 0) {
+		pr_err("virtio_crypto: Encryption failed!\n");
+		return ret;
+	}
+
+	return -EINPROGRESS;
+}
+
+static int virtio_crypto_ablkcipher_decrypt(struct ablkcipher_request *req)
+{
+	struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
+	struct virtio_crypto_request *vc_req = ablkcipher_request_ctx(req);
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	int ret;
+	/* Use the first data virtqueue as default */
+	struct data_queue *data_vq = &vcrypto->data_vq[0];
+
+	vc_req->ablkcipher_ctx = ctx;
+	vc_req->ablkcipher_req = req;
+
+	ret = __virtio_crypto_ablkcipher_do_req(vc_req, req, data_vq, 0);
+	if (ret < 0) {
+		pr_err("virtio_crypto: Decryption failed!\n");
+		return ret;
+	}
+
+	return -EINPROGRESS;
+}
+
+static int virtio_crypto_ablkcipher_init(struct crypto_tfm *tfm)
+{
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	tfm->crt_ablkcipher.reqsize = sizeof(struct virtio_crypto_request);
+	ctx->tfm = tfm;
+
+	return 0;
+}
+
+static void virtio_crypto_ablkcipher_exit(struct crypto_tfm *tfm)
+{
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	if (!ctx->vcrypto)
+		return;
+
+	virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
+	virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
+	virtcrypto_dev_put(ctx->vcrypto);
+	ctx->vcrypto = NULL;
+}
+
+static struct crypto_alg virtio_crypto_algs[] = { {
+	.cra_name = "cbc(aes)",
+	.cra_driver_name = "virtio_crypto_aes_cbc",
+	.cra_priority = 501,
+	.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+	.cra_blocksize = AES_BLOCK_SIZE,
+	.cra_ctxsize  = sizeof(struct virtio_crypto_ablkcipher_ctx),
+	.cra_alignmask = 0,
+	.cra_module = THIS_MODULE,
+	.cra_type = &crypto_ablkcipher_type,
+	.cra_init = virtio_crypto_ablkcipher_init,
+	.cra_exit = virtio_crypto_ablkcipher_exit,
+	.cra_u = {
+	   .ablkcipher = {
+			.setkey = virtio_crypto_ablkcipher_setkey,
+			.decrypt = virtio_crypto_ablkcipher_decrypt,
+			.encrypt = virtio_crypto_ablkcipher_encrypt,
+			.min_keysize = AES_MIN_KEY_SIZE,
+			.max_keysize = AES_MAX_KEY_SIZE,
+			.ivsize = AES_BLOCK_SIZE,
+		},
+	},
+} };
+
+int virtio_crypto_algs_register(void)
+{
+	int ret = 0;
+
+	mutex_lock(&algs_lock);
+	if (++virtio_crypto_active_devs != 1)
+		goto unlock;
+
+	ret = crypto_register_algs(virtio_crypto_algs,
+			ARRAY_SIZE(virtio_crypto_algs));
+	if (ret)
+		virtio_crypto_active_devs--;
+
+unlock:
+	mutex_unlock(&algs_lock);
+	return ret;
+}
+
+void virtio_crypto_algs_unregister(void)
+{
+	mutex_lock(&algs_lock);
+	if (--virtio_crypto_active_devs != 0)
+		goto unlock;
+
+	crypto_unregister_algs(virtio_crypto_algs,
+			ARRAY_SIZE(virtio_crypto_algs));
+
+unlock:
+	mutex_unlock(&algs_lock);
+}